Last week we were driving and the oil light came on, the engine started tapping, and when I looked there was oil all over the engine compartment and it looks like it was coming from the cylinder cover seal. Had it towed into a shop and they replaced the seal. Drove it home and about five miles later the whole thing happened again. Although this time I can't tell where the oil is coming from. I called the shop and they said that they would come out and pick up the truck but they haven't done it yet. They have not been good about communicating. Anybody have any thoughts about what is wrong with our truck?